Sync command from ansible

Sync the base of the command module from the latest ansible. There are a
few fixes in here that relate to python 3.

Change-Id: I474c2dd82bb11c43c52e6bba0507539951579780

zuul/ansible/library/command.py

@@ -19,6 +19,10 @@
 # You should have received a copy of the GNU General Public License
 # along with this software.  If not, see <http://www.gnu.org/licenses/>.
 
+ANSIBLE_METADATA = {'metadata_version': '1.0',
+                    'status': ['stableinterface'],
+                    'supported_by': 'core'}
+
 # flake8: noqa
 # This file shares a significant chunk of code with an upstream ansible
 # function, run_command. The goal is to not have to fork quite so much
@@ -34,7 +38,7 @@ module: command
 short_description: Executes a command on a remote node
 version_added: historical
 description:
-     - The M(command) module takes the command name followed by a list of space-delimited arguments.
+     - The C(command) module takes the command name followed by a list of space-delimited arguments.
      - The given command will be executed on all selected nodes. It will not be
        processed through the shell, so variables like C($HOME) and operations
        like C("<"), C(">"), C("|"), C(";") and C("&") will not work (use the M(shell)
@@ -76,30 +80,33 @@ options:
       - if command warnings are on in ansible.cfg, do not warn about this particular line if set to no/false.
     required: false
 notes:
-    -  If you want to run a command through the shell (say you are using C(<),
-       C(>), C(|), etc), you actually want the M(shell) module instead. The
-       M(command) module is much more secure as it's not affected by the user's
-       environment.
-    -  " C(creates), C(removes), and C(chdir) can be specified after the command. For instance, if you only want to run a command if a certain file does not exist, use this."
+    -  If you want to run a command through the shell (say you are using C(<), C(>), C(|), etc), you actually want the M(shell) module instead.
+       The C(command) module is much more secure as it's not affected by the user's environment.
+    -  " C(creates), C(removes), and C(chdir) can be specified after the command.
+       For instance, if you only want to run a command if a certain file does not exist, use this."
 author:
     - Ansible Core Team
     - Michael DeHaan
 '''
 
 EXAMPLES = '''
-# Example from Ansible Playbooks.
-- command: /sbin/shutdown -t now
+- name: return motd to registered var
+  command: cat /etc/motd
+  register: mymotd
 
-# Run the command if the specified file does not exist.
-- command: /usr/bin/make_database.sh arg1 arg2 creates=/path/to/database
+- name: Run the command if the specified file does not exist.
+  command: /usr/bin/make_database.sh arg1 arg2 creates=/path/to/database
 
-# You can also use the 'args' form to provide the options. This command
-# will change the working directory to somedir/ and will only run when
-# /path/to/database doesn't exist.
-- command: /usr/bin/make_database.sh arg1 arg2
+# You can also use the 'args' form to provide the options.
+- name: This command will change the working directory to somedir/ and will only run when /path/to/database doesn't exist.
+  command: /usr/bin/make_database.sh arg1 arg2
   args:
     chdir: somedir/
     creates: /path/to/database
+
+- name: safely use templated variable to run command. Always use the quote filter to avoid injection issues.
+  command: cat {{ myfile|quote }}
+  register: myoutput
 '''
 
 import datetime
@@ -117,6 +124,8 @@ import threading
 
 from ansible.module_utils.basic import AnsibleModule, heuristic_log_sanitize
 from ansible.module_utils.basic import get_exception
+from ansible.module_utils.six import b
+
 # ZUUL: Hardcode python2 until we're on ansible 2.2
 from ast import literal_eval
 
@@ -459,14 +468,14 @@ def main():
     delta = endd - startd
 
     if out is None:
-        out = ''
+        out = b('')
     if err is None:
-        err = ''
+        err = b('')
 
     module.exit_json(
         cmd      = args,
-        stdout   = out.rstrip("\r\n"),
-        stderr   = err.rstrip("\r\n"),
+        stdout   = out.rstrip(b("\r\n")),
+        stderr   = err.rstrip(b("\r\n")),
         rc       = rc,
         start    = str(startd),
         end      = str(endd),